The present invention relates generally to drive couplings, and more specifically to a double roller chain connector having a retainer and coupler shield.
Couplers utilizing a pair of sprockets placed end to end and connected by a double roller chain extending over the sprocket teeth are frequently utilized to connect two drive shafts. The double link chain and double sprocket arrangement permit some axial misalignment of the shafts while retaining direct drive of one shaft from the other. With some arrangements, a coupler joint is provided on the double link chain and a straight pin is utilized to connect end links after the chain is wrapped around the two sprockets. With some couplers rubber boots are stretched over the joint for protection from the environment. To cover the rotating shafts, long sheet metal shields often are required. Connecting the chain link around the sprockets can be a tedious and time-consuming job. Other types of chain connectors wherein the chain is supported over the sprockets by a cylindrical member can be expensive to manufacture and difficult to assemble. Providing adequate shielding for protecting the connection from the environment and for protecting the operator from the rotating connection has been a continuing problem because of the difficulty in assembling the joint or in providing a compact and economical shield.
It is therefore an object of the present invention to provide an improved chain coupler for connecting two shafts or the like. It is a further object to provide such a coupler which is relatively easy to assemble, relatively inexpensive and protects the connection from the environment. It is a further object to provide such a device having an improved shield.
It is still a further object of the present invention to provide an improved coupler for a pair of shafts or the like which may be connected quickly and easily and which provides improved shielding characteristics as compared with previously available couplers. It is yet another object to provide such a device which is relatively inexpensive to manufacture and easy to use.
A coupler constructed in accordance with the teachings of the present invention includes a drive sprocket and a driven sprocket placed end to end and wrapped with a double row chain to transmit drive from one sprocket to the other. The end links of the chain remain unconnected and a steel ring, sized to slide over the sprockets with the chain attached, holds the chain in the sprocket teeth while torque is transmitted through the joint. A coupler shield having a pair of identical halves which snap together are joined over the sprockets, chain and steel ring to maintain the steel ring over the sprockets. The shield can also spin freely with respect to the joint to provide protection for the operator. The shield halves, which are preferably fabricated from plastic with integral mating snap structures, are relatively light in weight and inexpensive to manufacture and provide good protection of the connector from the environment. In one embodiment of the invention, grooves on the sprocket hubs receive the ends of the shields for better sealing and axial stability. The structure provides a considerable advantage in time savings for assembly and disassembly of the connection.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the description which follows and from the drawings.